Chinese researchers have found a robust antibody against the SARS coronavirus remained in the bodies of recovered SARS patients for more than three years.

"The discovery will help in the research of a SARS vaccine and help find the best therapy if SARS returns," said Li Taisheng, head of the research group yesterday.

The group of researchers from the Peking Union Medical College Hospital and the Chinese Academy of Medical Sciences has been following 30 recovered SARS patients since March 2003, when the disease, also known as severe acute respiratory syndrome, began to spread in China.

Although the antibody declined moderately as time passed, it remained at a high level for over three years after the patients recovered, Li said.

"We presume that recovered SARS patients could have long-term immunity from the disease," Li said.

"More studies are needed to prove whether recovered SARS patients would have immunity from SARS for life."

He said the neutralizing antibody was the most protective of all antibodies in preventing the SARS coronavirus from invading healthy cells.

Pinpointing the neutralizing antibody would help researchers develop a more effective SARS vaccine, Li added.

SARS killed 809 people worldwide in 2003. The public's awareness of the disease is fading and many scientists have stopped research on it.

However, Chinese researchers have persisted.

Li said, "There are still many problems with SARS that cannot be explained. For instance, where did the virus come from? If it was from the civet cat, why did it spread to humans suddenly at that time? And why did it disappear as suddenly as it came? Will SARS come again?"

The research will help the prevention and control of large-scale disease outbreaks like SARS in the future, Li added.

Surveillance against the disease will be a top priority during the Spring Festival in southern Guangdong Province, the provincial health department said.

Civet cats, a raccoon-like mammal thought to be the origin of the SARS virus found in humans, are sold and consumed in Guangdong despite a ban.

"We know that eating civet cats is a tradition in these places, but we urge citizens to stop the practice for the sake of their own health," said Zhang Yonghui, head of the health supervision office under the department.

Editor: Yan